Quenya 

lá

please

[lá (3) interjection? "please" (reading of gloss uncertain)(VT45:25)]

mecin

adverb. please

fasta-

verb. please

Quenya [PE 22:119,124] Group: Mellonath Daeron. Published by

ecë nin?

please, may I?

mecin

please [= s.v.p.]

Quenya [PE 22:166] Group: Mellonath Daeron. Published by

á sac’ i fendë, mecin

close the door, please

iquista

noun. request; if you please, please

Sindarin 

linnathol?

will you sing (please)?

Sindarin [PE22/167] Group: Eldamo. Published by

listo

interjection. please!

Sindarin Group: Eldamo - neologism/reconstructions. Published by

Beware, older languages below! The languages below were invented during Tolkien's earlier period and should be used with caution. Remember to never, ever mix words from different languages!

Early Quenya

iqista

noun. a request; if you please, please

A noun appearing as ᴱQ. iqista “a request” in the Qenya Lexicon of the 1910s under the early root ᴱ√IQI “request, ask for” (QL/43). Tolkien said that “by itself it = if you please, please”.

Neo-Quenya: I would retain ᴺQ. iquista “request” for purposes of Neo-Quenya along with related words, based on the Neo-Root ᴺ√IKWI(S). For “please” as marker of politeness, I would use the later formation mecin.

Early Quenya [QL/043] Group: Eldamo. Published by

Qenya 

fasta-

verb. to please

ke·tuluva?

will you come, please?

le-tuluva?

will you come, please?

lá

interjection. (?please)

ási le·kare

come now, do it (please)